Drain trough for refrigerator



July 24, 1956 J. B. HORVAY 2,755,636

DRAIN TROUGH FOR REFRIGERATOR Filed Aug. 19, 1954 INVENTOR.

JULIUS B. HORVAY HIS ATTORNEY finite htats atet DRAIN 'rnouon non nurnronnaron Julius B. Horvay, Louisville, Ky, assignor to General Electric Company, a corporation of New York Application August 19, B54, Serial No. 451,020

4 Claims. (Cl. 62-103) This invention relates to household refrigerators and, more particularly, to a drain trough for a household refrigerator.

Drain troughs are employed in household refrigerators to collect moisture resulting from periodic defrosting of the evaporator of the refrigerator and moisture condensing on the walls of the refrigerator. When the trough is close enough to the evaporator to collect the moisture without splashing, the temperature of the drain trough or a portion thereof may remain below the freezing temperature of water most or all of the time whereby any moisture collected in the drain trough or the portion thereof freezes therein rather than flowing freely therefrom through suitable means to the exterior of the compartment. This, of course, is an undesirable condition and may result in a clogging of the trough and in water overflowing from the drain trough into the remainder of the compartment.

The freezing of the ice in the drain trough or a portion thereof may result in stalagmites building up in the trough or the portion thereof to such an extent that they eventually will reach the evaporator if the evaporator is disposed adjacent the trough. Since the building up of the ice in the trough or the portion thereof increases the thermal mass, it will be seen that it becomes increasingly difficult for the defrost system to operate when it depends on heat leakage into the cabinet. This increasing thermal mass of ice may eventually render the defrost system inoperative.

A primary object of the present invention is to provide drain trough arrangement that prevents freezing of the moisture collected in the drain trough.

Further objects and advantages of the invention will become apparent as the following description proceeds and the features of novelty which characterize the invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

in accordance with this invention, a drain trough is disposed on one Wall of a food storage compartment that is formed by the inner liner of a refrigerator. An evaporator is disposed in the upper portion of the compartment and inclined toward the wall on which the drain trough is disposed whereby defrost moisture from the evaporator is collected in the drain trough. This drain trough is of low thermal mass and has a high thermal diffusivity so that its temperature is maintained above the freezing temperature of Water when it is collecting defrost moisture from the evaporator. A portion of the drain trough is disposed in heat exchange relation with the wall on which it is mounted. Suitable means are provided to conduct the defrost moisture from the drain trough to outside the food storage compartment.

For a better understanding of the invention reference may be had to the accompanying drawing, in which:

Fig. l is a front elevational View partly in section of a portion of a household refrigerator embodying the present invention;

Fig. 2 is a sectional view taken along the line 2-2 of Fig. 1; and

Fig. 3 is a sectional view taken along the line 33 of Fig. 1.

Referring to the drawing and particularly Fig. 1, there is shown a refrigerator cabinet 1 having doors 2 and 3 connected thereto by suitable hinges 4 and 5. The cabinet includes an inner liner 6 spaced from an outer case 7 with suitable heat insulating material 8 disposed therebetween. The cabinet includes a freezing compartment 9 and a fresh food storage compartment 10. An evaporator 11 is disposed in the upper portion of the fresh food compartment 10 to cool the fresh food compartment. The evaporator 11 is a part of the well-known two-temperature evaporator system with the other evaporator (not shown) being disposed in heat exchange relation with the exterior of the walls of the freezing compartment 9 to maintain this compartment at the desired temperature to p eserve frozen foods. An insulating partition 12 separates the freezing compartment 9 from the fresh food compartment 10 to insulate the compartments from each other. Whlie the freezing compartment has been shown disposed above the fresh food compartment, it will be understood that the freezing compartment could be disposed below the fresh food compartment, if desired.

The door 2 provides access to the freezing compartment 9 while the door 3 provides access to the fresh food compartment 10. It will be understood that a single door could be employed in place of the two doors provided a separate smaller inner door is used to close the access opening of the freezing compartment 9 to maintain the freezing compartment at the desired temperature below freezing.

The evaporator 11 in the fresh food compartment 10 is defrosted after each on cycle by permitting the evaporator to rise to a temperature above the freezing temperature of water by heat leakage into the cabinet from the exterior thereof. By increasing the temperature of the evaporator above the freezing temperature of water, it is seen that any moisture formed on the evaporator as frost will be warmed to such an extent that it will drop therefrom into a drain trough 14. A portion of the drain trough 14 is in heat exchange relation with the rear wall of the inner liner. This drain trough 14 extends at least for the width of the evaporator 11 and preferably for a greater distance than the width of the evaporator 11 in order to collect any defrost moisture that may not drop vertically. The moisture flows from the drain trough 14 into a receptacle 15, which is disposed in one corner of the food storage compartment 10. From the receptacle 15 the moisture flows through a tube 16 to outside the outer case 7 This moisture may be disposed of by any suitable means outside the outer case '7 such as by evaporating the moisture by means of the heat of the machine compartment.

The inner liner 6 is provided with an opening 17 through which the evaporator 11 is inserted during assembly thereof; the drain trough 14 includes a vertical portion 18 that closes most of this opening. The upper end of the vertical portion 18 of the drain trough 14 has a portion 19 bent back at an angle (see Fig. 3) to errtend into the opening 17. The angular portion 19 has a substantially L-shaped cross-section that aids in holding the trough in position. Any moisture collecting on the inner liner 6 on the side exposed to the insulation 8 drops into the angular portion 19 from which it flows down the vertical portion 18 into a collecting portion 20, which is disposed at the lowermost edge of the vertical portion. The bottom of this collecting portion slopes from one side to the other so that any moisture collected therein from the evaporator 11 or the portion 19 flows freely therefrom into the receptacle 15. The collecting portion 20 has a depending portion 21 that provides a horizontal appearance to the drain trough 14 when it is mounted in the refrigerator rather than a sloping appearance if the collecting portion 20 were visible. A plurality of clips 22 are fixed to the back of the vertical portion 18 of the drain trough 14 and are aided by the angular portion 19 to secure the drain trough in position against the inner liner. These clips 22 hook over the bent portion 23 of the inner liner 6 as shown in Fig. 3. It will be understood that other suitable means could be employed for mounting the drain trough, if desired.

While a small part of the vertical portion 18 is in heat exchange relation with the inner liner 6, this heat exchange relation between the drain trough and the inner liner is not adequate under most circumstances to insure that the moisture collected in the drain trough 14 will not freeze therein. For example, the drain trough 14 or a portion thereof might be cooled below the freezing point of water during the refrigerating cycle and in a few isolated situations the inner liner 6 may drop below the freezing temperature of water. In order to maintain a constant temperature throughout the drain trough 14, the drain trough 14 is a low thermal mass member formed of any material having high heat conductivity, low density, and low specific heat or in other words, any material having high thermal diffusivity. To obtain a high degree of satisfactory performance, the drain trough is preferably formed of aluminum but other suitable materials may be employed provided they react quickly to temperature changes. Thus, when the cabinet air temperature increases due to heat leakage from the exterior of the cabinet during the defrosting operation, the drain trough 14 quickly warms up so that any water dripping therein due to defrosting will not freeze. By making the drain trough 14 of a material having high thermal diffusivity such as aluminum, a substantially constant temperature is maintained throughout the drain trough rather than a varying temperature in different portions thereof that might tend to cause ice build ups therein. Under some circumstances during operation of the refrigerating system, the cabinet air may be sufiiciently warm to allow the drain trough to remain above freezing at all times due to its being in heat exchange with the inner liner and exposed to the cabinet air so that moisture does not freeze therein. Thus, the water flows from the drain trough without any danger of it freezing therein.

While the invention has been disclosed with the defrosting depending on heat leakage into the compartment containing the drain trough, it will be understood that other defrosting methods could be employed such as hot gas or electric heating, for example.

While the present invention has been disclosed with the refrigerator having two compartments with each having its own evaporator with only the Warmer compartment employing the drain trough, it will be understood that the refrigerator could have a single evaporator with a baifie dividing the cabinet into two compartments.

The present invention has the advantage of insuring that moisture collecting in the food storage compartment of a refrigerator during defrosting is automatically removed therefrom.

While the present invention has been described by reference to a particular embodiment thereof, it will be understood that modifications may be made by those skilled in the art without actually departing from the invention. Therefore, the appended claims are intended to cover all such variations as come within the true spirit and scope of the invention.

1 claim:

1. In a refrigerator having an inner liner forming a food storage compartment including several walls, an evaporator disposed in the upper portion of said compartment and inclined toward one of said walls, an opening in said one wall, a drain trough disposed on said one wall below said evaporator and adjacent thereto whereby defrost moisture is collected from said evaporator, said drain trough having a low thermal mass and high thermal diffusivity whereby the temperature of said drain trough is maintained above the freezing temperature of water when said drain trough is collecting defrost moisture from said evaporator, a portion of said drain trough disposed in heat exchange relation with said one wall, another portion of said drain trough being disposed in said opening, and means to conduct the defrost moisture from said drain trough to outside said food storage compartment.

2. In a refrigerator having an inner liner forming a food storage compartment including several walls, an evaporator disposed in the upper portion of said compartment and inclined toward one of said walls, an opening in said one wall, a drain trough disposed on said one wall below said evaporator and adjacent thereto whereby defrost moisture is collected from said evaporator, said drain trough having a low thermal mass and high thermal diffusivity whereby the temperature of said drain trough is maintained above the freezing tempera ture of water when said drain trough is collecting defrost moisture from said evaporator, a portion of said drain trough disposed in heat exchange relation with said one wall, said drain trough comprising a vertical portion in contact with said one wall, said vertical portion closing most of said opening, an angular portion bent from a part of the upper edge of the vertical portion to extend into said opening, means to cooperate with said angular portion to hold said drain trough in position against said one wall, said drain trough having a collecting portion at the lowermost edge of the vertical portion, and means to conduct the defrost moisture from said drain trough to outside said food storage compartment.

3. In a refrigerator having an inner liner forming a food storage compartment including several walls, an evaporator disposed in the upper portion of said compartment and inclined toward one of said walls, an opening in said one wall, a drain trough disposed on said one wall below said evaporator and adjacent thereto whereby defrost moisture is collected from said evaporator, said drain trough having a low thermal mass and high thermal diffusivity whereby the temperature of said drain trough is maintained above the freezing temperature of water when said drain trough is collecting defrost moisture from said evaporator, a portion of said drain trough disposed in heat exchange relation with said one wall, said drain trough being of a greater width than said opening, said drain trough comprising a vertical portion in contact with said one wall, said vertical portion closing most of said opening, an angular portion bent from a part of the upper edge of the vertical portion to extend into said opening, means to cooperate with said angular portion to hold said drain trough in position against said one wall, said drain trough having a collecting portion at the lowermost edge of the vertical portion, and means to conduct the defrost moisture from said drain trough to outside said food storage compartment.

4. In a refrigerator having an inner liner forming a food storage compartment including several walls, an evaporator disposed in the upper portion of said compartment and inclined toward one of said walls, an opening in said one wall, a drain trough disposed on said one wall below said evaporator and adjacent thereto whereby defrost moisture is collected from said evaporator, said drain trough having a low thermal mass and high thermal diffusivity whereby the temperature of said drain trough is maintained above the freezing temperature of water when said drain trough is collecting defrost moisture from said evaporator, a portion of said drain trough disposed in heat exchange relation with said one wall, said drain trough being of a greater width than said opening, said drain trough comprising a vertical portion in con- 5 6 tact with said one wall, said vertical portion closing most to the other to drain defrost moisture therefrom, and of said opening, an angular portion bent from a part means to conduct the defrost moisture from said drain of the upper edge of the vertical portion to extend into trough to outside said food storage compartment. said opening, means secured to said vertical portion and extending into said opening cooperating with said angu- 5 References Cited in the file of this patent lar portion to hold said drain trough in position against UNITED STATES PATENTS said one wall, said drain trough having a collecting portion at the lowermost edge of the vertical portion, the 1,731,711 Davenport 1925 bottom of said collecting portion sloping from one end 2,606,426 Tucker 1952 

